I imagine going to "Replace with other content" and being able to check a box "Clone entity".

This would be quite useful, because many times our users don't want to edit all instances of an entity site-wide. They just want to clone a content entity so the changes only reflect in that instance of the app.

Yeah I have tried it as clean install and it looks very stable. Have not tried an update yet. You will have to get used to it as the UI is also completely redone so it looks different in the beginning but is works faster and smoother in the whole editing department